Remove NONE permissions in PublicFolders

In my Ex2010, I am unable to remove the users/group with NONE permissions in public folders.

I tried remove-PublicFolderClientpermission, RemoveUserFromRecursive.ps1 and even on console, but these groups still appear with permissions set to NONE.

Any idea why this is happening? And how to resolve it.

Prashanth - MCITP Enterprise Admin | Exchange Pro